Department of Pediatrics, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an City, Jiangsu Province, 223300, China.
Department of Anesthesiology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an City, Jiangsu Province, 223300, China.
Acta Biochim Pol. 2022 May 26;69(2):437-446. doi: 10.18388/abp.2020_5921.
MiR-101 has been reported to be involved in neuroinflammation, neuronal injury and neurotoxicity. However, the specific role and mechanism of miR-101 in ischemia/reperfusion (I/R)-induced neuronal injury remain largely unknown. Our study found that after oxygen-glucose deprivation/reperfusion (OGD/R) exposure, the level of miR-101 in SH-SY5Y cells was significantly decreased, which was accompanied by a decrease in cell viability, and an increase in LDH release and apoptosis. MiR-101 overexpression (miR-101 mimics) significantly promoted viability and inhibited LDH release and apoptosis in OGD/R-exposed SH-SY5Y cells. Luciferase reporter assay indicated that enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) was a direct target of miR-101, and EZH2 siRNA obviously increased the viability, inhibited LDH release and apoptosis in OGD/R-exposed SH-SY5Y cells. Besides, EZH2 siRNA could inhibit the activation of mitogen-activated protein kinase (MAPK14) signaling pathway and the MAPK14 agonist (anisomycin) could reverse EZH2 siRNA-induced increase in cell viability, and decreases in LDH release and apoptosis. Furthermore, when the methyltransferase activity of EZH2 was inhibited by its specific inhibitor GSK126, the level of miR-101 was increased in OGD/R-exposed SH-SY5Y cells. Additionally, EZH2 siRNA upregulated miR-101 expression in OGD/R-exposed SH-SY5Y cells. Taken together, our findings reveal that miR-101/EZH2 negative feedback signaling drives OGD/R-induced injury by activating the MAPK14 signaling pathway in SH-SY5Y cells.
miR-101 已被报道参与神经炎症、神经元损伤和神经毒性。然而，miR-101 在缺血/再灌注（I/R）诱导的神经元损伤中的具体作用和机制在很大程度上仍然未知。我们的研究发现，在氧葡萄糖剥夺/再灌注（OGD/R）暴露后，SH-SY5Y 细胞中的 miR-101 水平显著降低，伴随着细胞活力降低，LDH 释放增加和细胞凋亡增加。miR-101 过表达（miR-101 模拟物）显著促进了 OGD/R 暴露的 SH-SY5Y 细胞的活力，并抑制了 LDH 释放和细胞凋亡。荧光素酶报告基因检测表明，增强子 of zeste 2 多梳抑制复合物 2 亚基（EZH2）是 miR-101 的直接靶标，EZH2 siRNA 明显增加了 OGD/R 暴露的 SH-SY5Y 细胞的活力，抑制了 LDH 释放和细胞凋亡。此外，EZH2 siRNA 可以抑制丝裂原活化蛋白激酶 14（MAPK14）信号通路的激活，MAPK14 激动剂（anisomycin）可以逆转 EZH2 siRNA 诱导的细胞活力增加，以及 LDH 释放和细胞凋亡减少。此外，当 EZH2 的甲基转移酶活性被其特异性抑制剂 GSK126 抑制时，OGD/R 暴露的 SH-SY5Y 细胞中的 miR-101 水平增加。此外，EZH2 siRNA 在 OGD/R 暴露的 SH-SY5Y 细胞中上调 miR-101 的表达。总之，我们的研究结果表明，miR-101/EZH2 负反馈信号通过激活 MAPK14 信号通路驱动 SH-SY5Y 细胞的 OGD/R 诱导损伤。
